A packet-optical integrated switch without an optical transponder, includes: a packet line card configured to output an Ethernet packet signal to a pre-set output port; a packet switch fabric configured to transfer the packet signal from the packet line card to the output port previously set in a destination address included in the packet signal; a 10 gigabit Ethernet (10 GbE)/optical transport unit level 2 (OTU2) integrated line card configured to convert the packet signal from the packet switch fabric into an OTU2 optical signal having a pre-set wavelength; and a wavelength selection switch fabric configured to allocate the optical signal from the 10 GbE/OTU2 integrated line card to a pre-set wavelength division multiplexing (WDM) port by pre-set wavelength to exchange the optical signal to each port by wavelength, wherein the packet line card, the packet switch fabric, the 10 GbE/OTU2 integrated line card, and the wavelength selection switch fabric perform the reverse operations of the process, respectively.